Quick release device for presser mechanism of a sewing machine



A. QUICK RELEASE DEVICE FOR PRESSER MECHANISM R. FRITTS Aug. 6, 1968 OF A SEWING MACHINE Filed April 19, 1967 2 Sheets-Sheet l INVENTOR. Russell A. FriHs BY WXTTORNEY Witness Aug. 6, 1968 R. A. FRITTS QUICK RELEASE DEVICE FOR PRESSER MECHANISM OF A SEWING MACHINE 2 Sheets-Sheet 2 Filed April 19, 1967 44 INVENTOR Russell A. Fn'fls ATTORNEY izili i J l United States Patent O 3,395,662 QUICK RELEASE DEVICE FOR PRESSER MECHANISM OF A SEWING MACHINE Russell A. Fritts, Boonton Township, N.J., assignor to The Singer Company, New York, N.Y., a corporation of New Jersey Filed Apr. 19, 1967, Ser. No. 631,937 Claims. (Cl. 112235) ABSTRACT OF THE DISCLOSURE This disclosure relates to a quick release device for a presser mechanism of a sewing machine. More particularly, the disclosure relates to a device for adjusting the biasing force of the presser mechanism against the work supporting surface of the bed, which device has an actuating member, the turning of which effects release of the biasing force of the pressure mechanism to permit easy operator movement of the work for darning or the like.

Background of the invention There are various known devices for either adjusting the biasing force of the presser mechanism or completely releasing said bias. However, these devices though workable have failed to satisfy the need in that they are relatively intricate, usually require several threaded connections and may not be usable in existing machines.

Summary of the invention In accordance with the present invention the novel quick release device is adapted to regulate the force exerted by a spring biased presser mechanism mounted in the head of a sewing machine for longitudinal movement therein. Said device includes a sleeve member to which an actuating member is operatively connected. The sleeve member is nonrotatably mounted in the head and has aslot with a plurality of teeth therein. A pawl is radially anchored to the actuating member to collapsibly engage the slot teeth in a longitudinally adjustable position whereby on turning movement of the actuating member the pawl is released from the slot teeth to permit substantial unbiasing of the presser mechanism.

It is therefore an object of the present invention to provide an improved quick release device which overcomes the prior art deficiencies; which is simple, economical, and reliable; which has a few operating parts and is readily assembled; which is non-threadedly connected to the head; which snap locks in assembled position; which uses component parts that interconnect to prevent accidental removal thereof; which uses operator readable indicia to indicate the bias setting; which is easy to operate; while adapted for use in existing machines.

Other objects and advantages will be apparent from the following description of one embodiment of the invention and the novel features will be particularly pointed out hereinafter in the claims.

Brief description of the drawings This invention is illustrated in the accompanying drawings in which:

FIGURE 1 is a head and elevational view, partly in section of a sewing machine embodying the present invention.

FIGURE 2 is a greatly enlarged view, partly in section of the novel quick release device mounted in the head as shown in FIGURE 1.

FIGURE 3 is a sectional view taken substantially on the line 33 of FIGURE 2.

FIGURE 4 is a sectional view taken substantially along line 4-4 of FIGURE 2.

3,395,662 Patented Aug. 6, 1968 ice FIGURE 5 is a sectional view taken substantially along on the line 55 of FIGURE 2.

FIGURE 6 is an exploded perspective view of the quick release device, per se.

FIGURE 7 is a perspective rear elevational view of the improved quick release device showing the spring finger that prevents the upward removal thereof.

FIGURE 8 is a perspective head view of the improved quick release device adjusted to exert maximum biasing force on the presser mechanism.

FIGURE 9 is a perspective head view in which the actuating member of the improved quick release device has been turned to radially collapse the spring clip out of engagement with the slot teeth of the sleeve member.

FIGURE 10 is a sectional view taken substantially along line 10-40 of FIGURE 9 at a point just above the top of the collapsed spring clip.

FIGURE 11 is a perspective head view of the improved quick release device in the substantially unbiased or darning position.

Description of the invention In the drawings the novel quick release device, designated generally as 20, is illustrated as embodied in a conventional sewing machine having a frame including a bed 22 with a throat plate 24 and a head 26 which overhangs the bed. The presser mechanism, which is designed to press the work downwardly against the throat plate 24 and the feed-dogs 28 of the feeding mechanism, comprises a presser bar 30 mounted for longitudinal sliding movement in a bushing 32 in the head 26 and carrying a presser foot 34 at its lower end. A collar 36 is secured to the presser bar by a set screw 38 and carries a rearwardly directed guide arm 40 that overhangs the presser-lifter lever 42 and works in the usual slot in the head to prevent the presser bar from turning. The upper section 44 of presser bar 30 is of reduced diameter and extends upwardly from shoulder 46 to be telescoped within the lower ends of the novel quick release device .20. To bias the presser bar 30 downwardly, a presser bar spring 48 is coiled about section 44 with the lower end abutting shoulder 46 and the upper end engaged by a washer 50, that is loosely disposed about section 44 so as to readily slide thereon in response to the adjusted position of the quick release device 20 which bears against its upper surface to regulate the biasing force of spring 48.

The improved quick release device 20 illustrated in FIG- URES 2-6 that includes a sleeve member '52 into which is slidably disposed an actuating member 54 having a pawl member or spring clip 56 anchored thereto for engagement with the sleeve member 52.

The sleeve member 52 is cylindrica'lly shaped with the rolled outer edges forming an open axial seam 58 opposite which is an axial slot 60 extending upwardly from the bottom to about the midpoint of the sleeve.

The left side of slot 60 as seen in FIGURE 2 has a plurality of downwardly extending teeth 62 formed thereon to run from just below the enlarged upper end of slot 60 to a short distance above the bottom edge 61 thereof. The right side of slot 60 is formed integrally with a downwardly extending projection 63 that extends below the bottom edge 61 and has a vertical edge 64 that terminates in a stop shoulder 66. The upper end of sleeve member 52 has a radial tab 68 formed intermediate opening 58 and slot 60, on the same side as teeth 62. A spring finger 70 is formed on the opposite side, and is inclined outwardly and upwardly immediately adjacent the seam 58. Immediately above finger 70 an axial tab 72 projects upwardly from the top of sleeve member 52.

The outer diameter of sleeve member 52 is made to fit within a hole 74 in a boss 76 that is formed on a transverse partition 78 in head 26. Partition 78 is formed below a top plate 80 that has a hole 82 through which sleeve member 52 is disposed to pass through boss 76. Sleeve member 52 is angularly aligned by placing radial tab 68 in a radial slot 84 at the upper end of boss 76. Slot 84 serves the duel function of preventing sleeve member 52 from being turned and limiting its descent through boss 76. The vertical distance from the bottom of tab 68 to the top of spring finger 70 corresponds to that from the bottom of slot 84 to the bottom surface of boss 76 so that as seen in FIGURE 7 the spring finger 70 will expand outwardly in engagement with the bottom surface of boss 76 to prevent upward lifting of sleeve member 52. Accordingly, sleeve member 52 is nonrotatably locked in boss 76 with tab 72 extending upwardly of the top plate 80.

Actuating member 54 is substantially tubular and has a central longitudinal hole 88 extending from the bottom and terminating a short distance from the top. A knob 90 is formed at the top of the actuating member 54 and has a slight taper that extends from the fiat top outwardly to terminate in an inwardly extending shoulder 92. The

opposite slot 100. Indicia 102 is placed to be read in cooperation with the upper edge of tab 72, as best seen in FIGURE 7 to indicate the pressure setting or degree of biasing force being exerted by the presser mechanism. The longitudinal distance on the actuating member 54 from the shoulder 92 to the shoulder 96 is slightly greater than the distance on the sleeve member 52 from the top of tab 72 to the bottom edge 61.

Spring clip 56 is substantially U shaped and when engaged within slot 60 will be of slightly smaller diameter than the diameter of the body portion 94. As seen in the drawings its axial edges are turned outwardly to form a right flange 106 and a left flange 108 which flanges extend outwardly of slot 60. The upper edge of flange 108 is bent in the direction of teeth 62 to form a pawl finger 110 that engages teeth 62. Flange 106 will slidingly engage edge 64 of slot 60 and serve as a radial anchor during either increase of or release of the biasing force of the presser mechanism. This permits spring clip 56 to be radially collapsed so as to remove pawl finger 110 from immediate engagement with one of the teeth 62. In order to connect spring clip 56 to actuating member 54, an inwardly extending radial tab 104 is formed on the clip having a length susbtantially greater than the normal assembled clearance distance that will exist between the clip 56 and the sleeve member 52 as seen in FIGURES 4 and 10.

To assemble the quick release device 20, the actuating member 54 may be placed within the sleeve member 52 with shoulder 92 abutting tab 72. This exposes the shoulder 96 below the bottom edge 61 so that the spring clip 56 may be radially compressed and disposed about portion 98 with radial tab 104 being anchored in axial slot 100. Thereafter, on raising the actuating member 54, flanges 106 and 108 will be operatively disposed in slot 60. The stop shoulder 66 will act to prevent spring clip 56 and actuating member 54 from being lowered out of the sleeve member 52 during normal operation of device 20. Normally actuating member 54 will be placed within sleeve member 52 prior to the sleeve member being inserted into boss 56. This is done to facilitate connecting spring clip 56 to actuating member 54.

The improved quick release device forms a complete subassernbly in which the sleeve member 52 is operatively connected to the actuating member 54 through the interconnecting spring clip 56. The interconnecting tabs and slots prevent misalignment of device 20 which may readily be inserted into position in boss 76 whereby the upper section 44 of presser bar 30 will be telescoped into hole 88 so that the lower ends of actuating member 54 and spring clip 56 abut the upper surface of washer 50 and cause it to bear upon presser bar spring 48. In this manner operator influenced downward pressure on knob of actuating member 54 will cause pawl finger 110 to be rocked downwardly in teeth 62.

FIGURES 8-11 show the sequence of operation for quick release of the biasing force of the presser mechanism. The quick release device 20 will be used for such sewing operations as darning or to enable the operator to reset the presser mechanism at a lesser biasing force after quick release from the higher setting.

Accordingly, when the operator desires to quick release the biasing force or change it from the maximum shown in FIGURE 8, knob 90 will be turned counter-clockwise as indicated by the arrow 112 illustated in FIGURE 9. This forces spring clip 56 to radially collapse as shown in FIGURES 9 and 10 since it is anchored at spaced points by flange 106 and tab 104 to member 52 and 54 respectively. Thus flange 108 is forced to move in a direction of flange 106 and pawl finger is removed from engagement with teeth 62. Once the restraint on spring 48 is removed it will expand to substantially release the biasing force normally exerted by the presser mechanism and assume the greatly relaxed position shown in FIGURE 11. The upward force of spring 48 will push washer 50, and the abutted actuating member 54 and spring clip 56 upwardly to the darn position so that on flange 108 shifting away from flange 106 the sprin clip 56 will be located at the upper end of slot 60. The pawl finger 110 will be disposed in the enlarged upper opening of slot 60 and the presser mechanism will be in the darning position with the biasing force exerted by spring 48 amounting to only a light pressure.

To restore the normal sewing condition, the operator may depress knob 90 thus moveactuating member 54 downwardly causing pawl finger 110 to rock downwardly into engagement with teeth 62 at the desired pressure setting.

Spring clip 56 is disposed in slot 60 in slight radial compression so that flanges 106 and 108 will be pulling away from each other to keep pawl finger 110 in positive engagement with teeth 62. The flat bottom of the teeth serve to latch the pawl finger 110 in adjusted position while the inclined upper side corresponds to the incline of the pawl finger 110 and facilitates its downward rocking thereon.

Except for the spring qualities of clip 56 all the components of the improved quick release device 20 are relatively rigid and may be made of any suitable material, for example, the sleeve and clip may be metal and the actuating member may be of plastic.

It will be understood that there are changes in the details, materials, arrangements of parts and opzrating conditions which have been herein described and illustrated in order to explain the nature of the invention which may be made by those skilled in the art within the principles and scope of the invention as expressed in the claims.

Having thus set forth the nature of the invention, what I claim herein is:

1. A quick release device for a sewing machine adapted to regulate the force exerted by a spring biased presser mechanism mounted in the head of the sewing machine for longitudinal movement therein, said device comprising:

(a) a sleeve member nonrotatably mounted in the head,

(b) a slot formed in the sleeve member,

(0) a plurality of teeth formed in the slot,

(d) an actuating member operatively connected to the sleeve member to be shifted longitudinally thereof in engagement with the upper end of the presser bar, and

(e) a pawl means radially anchored to the actuating member to collapsibly engage the slot teeth in a longitudinally adjustable position and adapted on turning movement of the actuating member to be released from the slot teeth to permit substantial unbiasing of the presser mechanism.

2. The combination claimed in claim 1 wherein:

(a) the actuating member having a substantially cylindrical periphery, and disposed within the sleeve member,

(b) the lower end of the actuating member being of reduced diameter, and

(c) the pawl means being substantially U shaped and disposed about the lower end of the actuating member to permit the actuating member to slide relative the sleeve member.

3. The combination claimed in claim 2 wherein:

(a) the pawl means defining a spring member having a pawl finger, and

(b) at least one flange formed on the pawl means to extend radially outwardly into the slot to place the pawl finger into releaseable engagement with the teeth of the slot.

4. The combination claimed in claim 3 wherein:

(a) means formed in the slot to normally prevent the axial removal of the pawl means from the slot whereby the actuating member will be prevented from being removed from the sleeve member.

5. The combination claimed in claim 3 wherein:

(a) the sleeve means having a predetermined diameter,

(b) a knob formed on the upper end of the actuating member of larger diameter than the diameter of the sleeve member,

(0) the pawl means connected to the lower end of the actuating member and t0 co-act with the knob to prevent the removal of the actuating member from the sleeve member, and

(d) means locking the sleeve member in mounted position within the head.

6. A quick released device for a spring biased presser bar mechanism mounted in the head of a sewing machine, said device comprising:

(a) a sleeve member nonrotatably locked in the head,

(b) an actuating member slideably disposed in the sleeve member,

(c) a spring clip connected to the actuating member,

(d) a slot extending substantially longitudinally in the sleeve member with a plurality of teeth formed on one side thereof,

(e) flanges on the clip extending radially outwardly from the actuating member into biased engagement with the slot,

(f) a pawl formed on the spring clip to engage one of the teeth and adapted to be rocked downwardly to a lower tooth responsive to a downwardly force exerted on the acting member, and

(g) the spring clip being adapted to collapse radially on turning movement of the actuating member to remove the pawl from engagement with the teeth and to release the bias force of said pressure mecha- 7. The combination claimed in claim 6 wherein:

(a) the pawl is formed in the flange adjacent the teeth and biased into engagement therewith,

(b) the other flange to slideably engage the opposite side of the slot, and

(c) means radially anchoring the spring clip to the actuating member whereby on turning movement of the actuating member in a predetermined direction the pawled flange to be urged toward the other flange to unseat the pawl from engagement with the teeth and cause the substantial release of the biased force of the presser mechanism.

8. The combination claimed in claim 7 wherein:

(a) an indicator means formed at the upper end of the sleeve means at predetermined longitudinal distance from the slot means,

(b) indicia formed on the actuating member at a predetermined longitudinal distance from the pawl, and

(c) the indicia to co-act with the indicator means to successively indicate the degree of bias of the pressure mechanism responsive to the location of the pawl within the slot.

9. The combination claimed in claim 6 wherein:

(a) a longitudinal hole extending from the bottom of the actuating member toward top and adapted to slideably receive the upper end of the presser mechanism, therein, and

(b) abutment means disposed between the lower end of the actuating member and the spring of the presser mechanism.

10. The combination claimed in claim 9 wherein:

(a) the lower end of the actuating member having an outer periphery of reduced diameter,

(b) the spring clip being substantially U shaped and disposed about the lower end of the actuating member, and

(c) the spring clip being in longitudinal engagement between the actuating member and the abutment means to transmit at least a portion of the longitudinal forces therebetween.

References Cited UNITED STATES PATENTS 55 PATRICK D. LAWSON, Primary Examiner. 

